Document Type Definition

A Document Type Definition (DTD) is a set of rules that defines the structure and allowable elements within an electronic document, like XML. It specifies what tags or components can appear, their order, and how they relate to each other. Think of it as a blueprint or blueprint standard that ensures documents follow a consistent format, making them easier to read, validate, and process across different systems or applications. DTDs help maintain data integrity and clarity by clearly outlining what’s permitted within a document's framework.